1. Field of the Invention
The present invention relates to a paint sludge separating tank, and more particularly to a paint sludge separating tank for separating and removing paint components from a liquid used for cleaning and removing spray mist from exhaust air from spraying equipment, the tank comprising a sludge drain formed on an upper end of a reservoir region for discharging paint sludge floating on a surface of stored liquid, and a liquid feeder for feeding paint-containing liquid to an upper position of the reservoir region horizontally spaced from the sludge drain.
2. Description of the Related Art
FIG. 6 shows a paint sludge separator tank of the type noted above. Waste liquid W under treatment is supplied to upper positions of a reservoir region horizontally remote from a floating sludge drain 12, whereby horizontal flows V are formed on the upper part of stored liquid W, flowing from the liquid supply positions toward the floating sludge drain 12. Paint sludge S including paint components of the liquid under treatment and floating on the liquid is collected toward the sludge drain 12 by the upper horizontal flows V. The tank includes a skimmer 13 or the like for smoothly and efficiently separating the floating paint sludge S and discharging the sludge S along the upper flowing direction to the sludge drain 12.
Conventionally, the liquid W to be treated is supplied to the tank through a feed pipe 8a extending to the upper positions of the reservoir region horizontally remote from the floating sludge drain 12. The feed pipe 8a has opening ends disposed in the stored liquid. See U.S. Pat. No. 4,722,791, for example.
According to the above liquid feeding construction, however, the upper part of the stored liquid is disturbed and ascent of the paint sludge S to the liquid surface hampered under the influence of the dynamic pressure of the liquid delivered for treatment. In addition, the liquid being delivered is obstructive to floating stability and collection of the floating sludge S by the horizontal flows V of the upper part of the liquid. This results in a reduced efficiency of separating the paint sludge.